San Francisco

Geological Study

By

Emily Williams

Victoria Hogg

Fault Lines of San Francisco

• 7 named fault lines.• Large probability

around Bay area.• Major earthquakes

in the past.• 60% chance of a

damaging earthquake in the next 30 years.

http://pubs.usgs.gov/gip/2005/15/

Damage during Earthquakes…

• Shaking - Magnitude

- Duration

- Distance

• Type of soil

• Land sliding

• Liquefaction

• Type of buildingAlthough miles from the fault, many San Francisco's streets were rippled and torn. Shown here is a crack near 18th Street looking east to Folsom Street in San Francisco.

http://quake.wr.usgs.gov/info/1906/soil.html

Geology

• Complex Geology.• Iron & Magnesium formed deep in the earth

brought to the surface.• Sand & gravel deposits from streams and

rivers.• Reclaimed Land.

• Constant movement because of San Andreas fault.

Where does damage occur?

http://pubs.usgs.gov/gip/2005/15/http://www.nps.gov/prsf/geology/geomap.htm

Landslides & Liquefaction

http://geology.about.com/library/weekly/aa120300a.htm

Engineering Issues

• Foundation• Soft story• Renovation of old buildings - Retrofit

• Engineering Design• Design codes• Monitoring buildings & bridges• Location of construction

Conclusion

Improvements:

• Knowledge

• Materials

• Technology

• Engineering

• Probability problem